1. Field of the Invention
The present invention relates to sod cutting machines having special utility on sod farms where sod is grown commercially.
2. Prior Art
Lawn grass is commonly grown from seed in sod farms measuring a number of acres in area, and sod farm acreages in excess of fifty acres are not uncommon. Sod grown in sod farms must be cut in small sections for delivery to the nursery or end user. Commonly each sod section has a rectangular configuration measuring two feet by four feet. The sod sections are stacked or rolled together on pallets on a transport vehicle.
In order to cut the growing sod into rectangular sections, machines having a series of parallel rotary disk cutters have been utilized. The cutter disks are spaced apart in a row configuration transversely of the movement direction of the machine. A farm tractor may be used to pull the machine along the sod surface in a straight line. As the machine is pulled over the sod surface, the cutter disks form parallel slits in the sod surface.
The machine may be pulled back and forth across the grass field to form a large number of parallel slits in the sod surface. Then, by pulling the machine back and forth in a transverse direction, crossing slits are formed in the sod surface. The criss-crossed slits have a checkerboard configuration to define rectangular sod sections sized for removal from the land surface for transportation to a nursery or end user.
When sod is grown directly in the natural earth surface, it is necessary to shave or sever the grass root system from the earth base by moving a knife blade mechanism horizontally underneath the root system. In some cases, sod is grown on plastic sheets previously placed on the earth surface. A sod-growing system of this type is shown in my U.S. Pat. No. 4,934,094. In such situations, it is unnecessary to run a knife mechanism under the sod sections. The rectangular sod sections can be lifted from the plastic sheet without mechanically severing the grass root system from the plastic sheet.
The following U.S. patents show sod cutting machines designed to form crossing slits in growing sod: U.S. Pat. No. 1,706,831 to J. Watson; U.S. Pat. No. 2,051,977 to Winston et al.; U.S. Pat. No. 2,617,347 to H. Provost; U.S. Pat. No. 2,998,081 to Hartmangruber et al.; and U.S. Pat. No. 3,807,504 to J. Nunes, Jr.